Is that one word or two?

You can never know for sure unless you look it up, but there are some general rules for when you should keep words separate and when you should put them together.

Lately I’ve been having trouble with compound words, such as timeframe, payoff, and placeholder.

Are these one word or two? After 10-plus years as a professional writer and editor, shouldn’t I know the rules for compound words by now? Why am I still asking myself these questions?

As it turns out, the rules for compound words aren’t straightforward. (Or is that straight forward?)

“Compound words generally develop over time through use. As people continue to use two or more previously unrelated words together, the combination gains acceptance. Unfortunately, this progression doesn’t follow a consistent, regular pattern. Word experts can’t even agree on rules for compound words,” says the website

This is why style guides differ on whether compound words such as health care and website are one word or two. The only way to be certain is to look it up in the dictionary (though dictionaries differ on some terms), but you can also follow these guidelines:

Compound nouns are usually written as one word.

You should schedule a checkup with your doctor.
Our last editor had a breakdown over serial commas.
What is the payoff for having a house style guide?

Compound verbs are generally written as two.

You should check up on those test results.
Please break down your last paragraph into shorter sentences.
I hope to pay off my student loans by June.

Compound adjectives and adverbs are very often written as two words or with a hyphen.

What should a woman wear to a black-tie event?
The cake landed upside down.
The upside-down painting confused us all.

The exception to this rule: Never hyphenate phrases that are created with adverbs ending in –ly.

Our offices were bigger in the recently-renovated building.
April had the dazed look of a newly hired media relations professional.

Another tip: Say the phrase out loud. If you enunciate each word separately, it’s probably written as two words.

The cutbacks were disastrous for employee morale.
I have to cut back on my consumption of chocolate.

Of course, when in doubt, consult a dictionary or your style guide.

Ragan readers, which compound words give you headaches?

Laura Hale Brockway is an Austin-based writer and editor and a regular contributor to PR Daily. Read more of her work at

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